I want to combine several textures... Bump, displacement, diffuse, specular but I don't know the node combination. A screenshot would be nice
If i understood the question here the answer

With the powerful addon Node Wrangler in built in Blender you can set the node automatically.

Make a folder and paste all the images (Bump, displacement, diffuse, specular).

With the Principle BSDF Node selected Press Ctrl+Shit+T

A pop-up which need to access all the images made above folder. Select all (Press A) 

Press Principle BSDF Setup and your done . Render it with F12